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991.
Use of tomographic measuring techniques for process engineering studies . Tomographic measuring techniques have so far been employed almost exclusively in medicine and for testing of materials. They permit determination of experimental values for all local coordinates of a given volume at a given time. Classical tomography can be used for measurements only in stationary fields of flow, temperature, and concentration since the object has to be irradiated from as many directions as possible during a finite time interval. In the case of transient events, however, it is necessary to acquire all these values at the same point in time. If transparent fluids are present then coherent light is suitable for irradiation and holographic interferometry for recording the measured values. Since irradiation must take place simultaneously from several directions, the number of recording angles should be kept to a minimum. It is also necessary to employ mathematical procedures for image reconstruction in order to ensure adequate accuracy of the measured values. 相似文献
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The formation of a 1:1 polymer-polymer complex from poly(acrylic acid) and poly(vinyl methyl ether) has been detected by viscosity measurements in aqueous solution, and the glass transition temperature of the isolated complex has been determined. Infrared spectroscopy indicates that specific hydrogen bonding occurs between the components of the complex. Miscible blends of the two polymers can also be formed (at all compositions) and, although hydrogen bonding occurs, the structures of the blends are likely to be dissimilar to that of the complex. 相似文献
995.
A new plasma ion source for in situ keV He ion bombardment of solid state samples or thin films was designed and built for ion fluences between 1 × 10(12) and 1 × 10(17) ions/cm(2). The system was designed to be mounted to different diffraction chambers for soft x-ray resonant magnetic scattering. Without breaking the vacuum due to He-ion bombardment, structural and magnetic modifications of the samples can be studied in situ and element specifically. 相似文献
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Alexey Cheptsov Bastian Koller Davide Adami Franco Davoli Szymon Mueller Norbert Meyer Paolo Lazzari Stefano Salon Johannes Watzl Michael Schiffers Dieter Kranzlmueller 《Computer Standards & Interfaces》2012,34(6):476-484
Despite the tremendous growth of the capacity of computation and storage IT solutions over the last years there is still a deep mismatch between the e-Infrastructures and the e-Science applications that use instruments, sensors, and laboratory equipment. The efficiency of using instruments in a remote way, i.e. Remote Instrumentation, might be largely improved by integration with the existing distributed computing and storage infrastructures, like Grids. The paper discusses major activities towards the e-Infrastructure for Remote Instrumentation – a Grid-based Information and Communication Technology environment capable of covering all the issues arising around enabling Remote Instrumentation for e-Science applications. 相似文献
999.
Fully autonomous navigation has been widely investigated for several decade of years; however, a safe and reliable navigation is still a daunting challenge in terrains containing vegetation. To improve the mobility capability of recent autonomous navigation systems, an additional vegetation detection function has been proposed. Since many proposals of generating vegetation classifier as well as suggestions of using different sensors to implement the function exist, a structured overview is required for vegetation detection in the context of outdoor navigation. Therefore, this paper studies and compares the accuracy and efficiency of existing vegetation detection approaches in a structured way. Furthermore, a new vision system set-up which combines CMOS sensor and Photo Mixer Device sensor with a near-infrared lighting system is also introduced to simultaneously provide depth, near-infrared and color images at high frame rate. Those near-infrared and color information are then used to compute vegetation index or train vegetation classifier to completely realize a real-time robust vegetation detection system. In this paper, a modification of the normalized difference vegetation index is devised, which is then defined as the new standard form of vegetation index for such vision system integrated with an additional lighting system. Finally, we will show the out-performance of the proposed approach in comparison with more conventional ones. 相似文献
1000.
Luis Antunes Lance Fortnow Dieter van Melkebeek N.V. Vinodchandran 《Theoretical computer science》2006
We introduce Computational Depth, a measure for the amount of “nonrandom” or “useful” information in a string by considering the difference of various Kolmogorov complexity measures. We investigate three instantiations of Computational Depth:
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- Basic Computational Depth, a clean notion capturing the spirit of Bennett's Logical Depth. We show that a Turing machine M runs in time polynomial on average over the time-bounded universal distribution if and only if for all inputs x, M uses time exponential in the basic computational depth of x. 相似文献